Purpose: :
To evaluate the potential of Typan blue (TB) for intra-operativestaining of the internal limiting membrane (ILM) and epiretinalmembranes (ERM) with respect to perceivable contrast.

Methods: :
In a retrospective clinical case-series we analyzed 44 consecutivechromovitrectomy interventions in 44 patients with macular holes(MH), epiretinal fibrosis (ERF), vitreoretinal traction syndromes(VRTS) or persistent macular edema (PME). Of the 44 enrolledsubjects, 15 underwent TB, 14 Indocyanine green (ICG) and 15Brilliant blue G (BBG) chromovitrectomy. Main outcome measurewas the color contrast between stained ILM or ERM and the underlyingunstained tissue as it is perceived by the human eye. Perceivedcontrasts were determined in the CIE 1976 (L*, a*, b*) colorspace by means of objective, quantitative video-based semi-automatedchromaticity difference measurements. This color space is conceptuallyuniform and changes of the same visual importance result inthe same difference (Euclidean distance) in the color space.

Results: :
Euclidian distances produced by TB were significantly higherfor ERM (7.67) than for the ILM (5.85, p=0.01793). Euclidiandistances for the ILM were similar with the use of both TB (5.85)and BBG (6.11, p=0.7164) but significantly higher after theapplication of ICG (16.35, p=2.2e-16).

Conclusions: :
TB has an affinity to both the ILM and ERM, where it stainsERM significantly better than the ILM. TB staining capacityfor the ILM is equivalent to that of Brilliant blue G (BBG),but significantly inferior to the contrast provided by Indocyaninegreen (ICG).